builtins.c (purge_builtin_constant_p): Handle subreg of constant_p_rtx too.

* builtins.c (purge_builtin_constant_p): Handle subreg of
constant_p_rtx too.

From-SVN: r63490

gcc/ChangeLog

 2003-02-26  Alexandre Oliva  <aoliva@redhat.com>
 
+	* builtins.c (purge_builtin_constant_p): Handle subreg of
+	constant_p_rtx too.
+
 	* function.c (assign_stack_local_1): Truncate constant added to
 	frame_pointer_rtx or virtual_stack_vars_rtx for Pmode.
 

gcc/builtins.c

@@ -4952,9 +4952,12 @@ purge_builtin_constant_p ()
   for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
     if (INSN_P (insn)
 	&& (set = single_set (insn)) != NULL_RTX
-	&& GET_CODE (SET_SRC (set)) == CONSTANT_P_RTX)
+	&& (GET_CODE (arg = SET_SRC (set)) == CONSTANT_P_RTX
+	    || (GET_CODE (arg) == SUBREG
+		&& (GET_CODE (arg = SUBREG_REG (arg))
+		    == CONSTANT_P_RTX))))
       {
-	arg = XEXP (SET_SRC (set), 0);
+	arg = XEXP (arg, 0);
 	new = CONSTANT_P (arg) ? const1_rtx : const0_rtx;
 	validate_change (insn, &SET_SRC (set), new, 0);